Forked from odinserj/DisableMultipleQueuedItemsFilter.cs
Created
March 26, 2019 02:49
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public class DisableMultipleQueuedItemsFilter : JobFilterAttribute, IClientFilter, IServerFilter | |
{ | |
private static readonly TimeSpan LockTimeout = TimeSpan.FromSeconds(5); | |
private static readonly TimeSpan FingerprintTimeout = TimeSpan.FromHours(1); | |
public void OnCreating(CreatingContext filterContext) | |
{ | |
if (!AddFingerprintIfNotExists(filterContext.Connection, filterContext.Job)) | |
{ | |
filterContext.Canceled = true; | |
} | |
} | |
public void OnPerformed(PerformedContext filterContext) | |
{ | |
RemoveFingerprint(filterContext.Connection, filterContext.Job); | |
} | |
private static bool AddFingerprintIfNotExists(IStorageConnection connection, Job job) | |
{ | |
using (connection.AcquireDistributedLock(GetFingerprintLockKey(job), LockTimeout)) | |
{ | |
var fingerprint = connection.GetAllEntriesFromHash(GetFingerprintKey(job)); | |
DateTimeOffset timestamp; | |
if (fingerprint != null && | |
fingerprint.ContainsKey("Timestamp") && | |
DateTimeOffset.TryParse(fingerprint["Timestamp"], null, DateTimeStyles.RoundtripKind, out timestamp) && | |
DateTimeOffset.UtcNow <= timestamp.Add(FingerprintTimeout)) | |
{ | |
// Actual fingerprint found, returning. | |
return false; | |
} | |
// Fingerprint does not exist, it is invalid (no `Timestamp` key), | |
// or it is not actual (timeout expired). | |
connection.SetRangeInHash(GetFingerprintKey(job), new Dictionary<string, string> | |
{ | |
{ "Timestamp", DateTimeOffset.UtcNow.ToString("o") } | |
}); | |
return true; | |
} | |
} | |
private static void RemoveFingerprint(IStorageConnection connection, Job job) | |
{ | |
using (connection.AcquireDistributedLock(GetFingerprintLockKey(job), LockTimeout)) | |
using (var transaction = connection.CreateWriteTransaction()) | |
{ | |
transaction.RemoveHash(GetFingerprintKey(job)); | |
transaction.Commit(); | |
} | |
} | |
private static string GetFingerprintLockKey(Job job) | |
{ | |
return String.Format("{0}:lock", GetFingerprintKey(job)); | |
} | |
private static string GetFingerprintKey(Job job) | |
{ | |
return String.Format("fingerprint:{0}", GetFingerprint(job)); | |
} | |
private static string GetFingerprint(Job job) | |
{ | |
string parameters = string.Empty; | |
if (job.Arguments != null) | |
{ | |
parameters = string.Join(".", job.Arguments); | |
} | |
if (job.Type == null || job.Method == null) | |
{ | |
return string.Empty; | |
} | |
var fingerprint = String.Format( | |
"{0}.{1}.{2}", | |
job.Type.FullName, | |
job.Method.Name, parameters); | |
return fingerprint; | |
} | |
void IClientFilter.OnCreated(CreatedContext filterContext) | |
{ | |
} | |
void IServerFilter.OnPerforming(PerformingContext filterContext) | |
{ | |
} | |
} |
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